Blade or vane applicable to wind wheels, propellers, and the like



Nov. 15, 1927. 1,649,057

A. BUNKENBURG BLADE on mm APPLICABLE TO WIND wxmnns, PROPELLERS, mm THE LIKE File dJan.25, 1927 l 'lC.

rist AUGUET BUNKENB'URG. OF HAMBURG, GERMANY.

BLADE QB VANE .[TLPTELICABLE 'lO MIND WHEELS, PBUPELLERS, AND TEE LIKE.

Application filed January 25, 1927, Serial The present invention relates to the construction of blades or vanes applicable to windwheels, propellers and the like, wherein a plurality of blades are arranged one be hind another. Arrangements are known in which such blades, of ordinary helical form, are in axial registration or alignment instead of being relatively staggered. More over, it has been proposed, in the case of individual blades of a single propeller, to give them a compound-curved form in cross section, one part being concave and another part convex. According to the present invention, the blades arranged one behind another, in addition to being located in axial alignment, are each of a form which presents in cross-section a curve of double or contrary tlexure. By this arrangement, a suction ac tion, increasing with the speed when the blades are rotated, is set up in the channels located between the blades, so that the propelling or impelling force is utilized to the greatest possible extent.

A constructional form of the invention applied to a wind-wheel is illustrated by way of example in the accompanying drawings, and the invention is hereinafter particularly described with reference to the said constructional form.

In the said drawings Figure 1 is a front elevation of a windwheel,

Figure 2 a side elevation of the same, and

Figure 3 is a transverse section through the blades.

07 is the shaft of an air power machine car rying the blades (Z (Z on the arms 0 0 which are diametrically opposed but preferably made in one piece and rigidly secured to the shaft a by means of the hub 22. The blades (Z al which, in the constructional example given in the drawings, are substantially rectangular at their outer edges as viewed from the front, are each formed, in the direction of their width, in a curve of double or contrary flexure, and the curves of the diametrically opposite blades are relatively opposed, as clearly shown in Figure 3, so that they re semble the screw form of propeller.

As wind-wheels with a few comparatively narrow blades give the maximum effective power, the blades (Z d are of such superficial area, that each pair occupies about the elevt of the circle which they describe heir rotation.

No. 163,534, and in. Geri-unity April 6, 1925.

According to the present invention and for the purpose of completely utilizing the power of the wind, a plurality of diametrically opposite arms 0 c are arranged on the shaft a one behind the other with the blades (Z (Z and united into a rigid entity, so that curved channels of small width will be formed between the blades (Z and the blades (Z respectively. The union of the successively arranged blades cZ al into a rigid entity is preferably efiected by peripherally aiiixed closing members 6 6 a series of cells made up of curved channels being thus formed.

The wind striking against the front blades (Z (l curved in opposed directions gives rise to a component of force, by which rotary movement of the blades and consequently of the shaft (4 will be set up. The blades located in the rear of the front blades d al and thereby shielded from the direct action of the wind, participate in this rotary movement and produce a suction action in consequence of the channels located between them which are closed at the periphery, the inherent force of the wind streaming by the front blades d al being thus utilized. This results in an increase in the speed of rotation of the shaft a and a correspondingly enhanced effective power. With a wind velocity of 8 meters per second, in an air power engine fitted with blades of the present kind of only 2 meters diameter a. circumferential .speed of the blades of over 300 meters per second has been attained. The capacity of the air power engine increases proportionately with the acceleration of the speed of the wind, as with an increased number of revolutions of the shaft a the suction capacity in the curved channels between the blades (Z (Z will increase.

The blades described, in addition to being used for power producing wind-wheels can also be employed as a propelling medium for aircraft, for land and water conveyances and for ventilating purposes.

It is to be understood that the construc tional form illustrated in the drawings is given merely as an example, and that modifi cations may be made according to requirements in the construction and in the sizes of the respective parts without departing from the essential features of the invention.

Having described my invention, I declare that what I claim and desire to secure by Letters Patent is:- g

'5..- lin a wind wheel, propeller er the like,

lllti a plurality of blades arranged one behind another in axial alinement said blades being each formed, in the direction of its width, in a curve of double or contrary flexure, a plate rigidly connecting the blades at, their outer ends and closing the space between them, substantially as and for the purposes set forth.

2. In a wind-wheel, propeller or the like,

10 the combination of a plurality of blades arranged one behind another in axial alignment each of said blades being formed 1n the direction of its width in a curve of double AUGUST BUNKENBURG. 

